The invention relates to a field effect transistor comprising a source, a drain and a channel, respectively formed by source, drain and channel materials, the source, drain and channel materials being selected such that, for a NMOS type transistor, the electronic affinity Xd of the drain material is lower than the electronic affinity Xc of the channel material and such that, for a PMOS type transistor, the upper level Ed of the valence band of the drain material is higher than the upper level Ec of the valence band of the channel material.